KR102500625B1 - Image processing device, display device having the same, and image processing method of the same - Google Patents

Abstract

The image processing device includes a region divider configured to receive image data, convert the image data in pixel row units to generate converted data, and generate region division information for dividing the image data into a plurality of regions based on the converted data; A luminance detector that detects the region maximum luminance and region minimum luminance of each region based on the image data and region division information, and a correction that corrects the contrast of each region based on the region division information, region maximum luminance, and region minimum luminance. It includes a correction unit that generates image data.

Description

Image processing device, display device including the same, and image processing method thereof

The present invention relates to an image processing device, a display device including the same, and a driving method thereof.

Recently, various flat panel display devices capable of reducing the weight and volume, which are disadvantages of cathode ray tubes, are being developed. Flat panel display devices include Liquid Crystal Display (LCD), Field Emission Display (FED), Plasma Display Panel (PDP), and Organic Light Emitting Display (OLED). ), etc. In particular, the organic light emitting display device has been spotlighted as a promising next-generation display device because it has various advantages such as a wide viewing angle, fast response speed, thin thickness, and low power consumption.

To improve the picture quality of a display device, a method of dividing an image into a plurality of areas and correcting the picture quality for each area is used. Methods of dividing an image into a plurality of regions include methods of setting threshold voltages, extracting outlines within pixels, or dividing regions according to pixel values by creating a histogram. These methods have a problem in that they require a memory for storing entire image data, a frame memory for storing frame data, and an arithmetic device.

One object of the present invention is to provide an image processing device capable of improving display quality.

Another object of the present invention is to provide a display device capable of improving display quality.

Another object of the present invention is to provide an image processing method of a display device capable of improving display quality.

However, the object of the present invention is not limited to the above object, and may be expanded in various ways without departing from the spirit and scope of the present invention.

In order to achieve one object of the present invention, an image processing apparatus according to embodiments of the present invention receives image data, converts the image data in pixel row units to generate converted data, and based on the converted data a region dividing unit generating region division information for dividing the image data into a plurality of regions; a luminance detector detecting a region maximum luminance and a region minimum luminance of each region based on the image data and the region division information; and a correction unit configured to generate correction image data for correcting the contrast of each region based on the region division information, the maximum luminance of the region, and the minimum luminance of the region.

According to an embodiment, the correction unit may generate the corrected image data of the current frame based on the region division information of the image data supplied from the previous frame, the region maximum luminance, and the region minimum luminance.

According to an embodiment, the region divider may filter the image data in pixel row units using a linear filter to generate the converted data, and determine boundaries of the regions based on the converted data.

According to an embodiment, the linear filter may be selected from a group including any one of a high pass filter and a band pass filter.

According to an exemplary embodiment, the region divider outputs a histogram representing a luminance distribution corresponding to the image data in units of pixel rows as the converted data, compares the histograms of neighboring pixel rows, and determines boundaries of the regions. can decide

According to an embodiment, the region divider compares the histograms of the neighboring pixel rows, and when the frequency of the image data having the same luminance is equal to or greater than a preset threshold, the neighboring pixel rows are included in the same region. and if the frequency of the image data having the same luminance is less than the threshold value, it may be determined that the neighboring pixel rows are included in different regions.

In an exemplary embodiment, the region division unit may include a line memory storing the conversion data in units of pixel rows.

According to an exemplary embodiment, the luminance detection unit detects a maximum luminance and a minimum luminance of the image data in units of pixel rows, compares the maximum luminance and the minimum luminance of the pixel rows in each area, and The region maximum luminance and the region minimum luminance of each region may be detected.

According to an embodiment, the correction unit may extend the maximum luminance of the region and the minimum luminance of the region for each region.

In order to achieve another object of the present invention, a display device according to embodiments of the present invention converts a display panel including a plurality of pixels and image data corresponding to an image displayed on the display panel for each pixel row; an image processor configured to divide the image data into a plurality of regions based on the conversion data, and to generate correction image data for correcting contrast of each region based on a region maximum luminance and a region minimum luminance of each region; A data driver generating a data signal based on the corrected image data and supplying the data signal to the pixels, a scan driver supplying a scan signal to the pixels, and a control signal controlling the data driver and the scan driver. It may include a timing control unit that generates.

According to an embodiment, the image processing unit may divide the regions based on the image data supplied from a previous frame and generate the corrected image data of the current frame based on region division information for dividing the regions. .

According to an embodiment, the image processing unit may filter the image data in pixel row units using a linear filter to generate the converted data, and determine boundaries of the regions based on the converted data.

According to an exemplary embodiment, the image processing unit outputs a histogram representing a luminance distribution corresponding to the image data in units of pixel rows as the converted data, compares the histograms of neighboring pixel rows, and determines boundaries of the regions. can decide

According to an embodiment, the image processing unit may expand the maximum luminance of the region and the minimum luminance of the region for each region.

In order to achieve another object of the present invention, an image processing method of a display device according to embodiments of the present invention generates converted data by converting image data in pixel row units, and converts the image data based on the converted data. Dividing into a plurality of regions, detecting the region maximum luminance and region minimum luminance of each region based on the image data, and the contrast of each region based on the region maximum luminance and the region minimum luminance It may include generating correction image data for correcting .

According to an embodiment, the transformed data is generated by filtering the image data in pixel row units using a linear filter, and boundaries of the regions may be determined based on the transformed data.

According to an embodiment, the linear filter may be selected from a group including any one of a high pass filter and a band pass filter.

According to an embodiment, a histogram representing a luminance distribution corresponding to the image data in units of pixel rows is output as the converted data, and boundaries of the regions may be determined by comparing the histograms of neighboring pixel rows.

In an exemplary embodiment, the dividing of the region may include comparing the histograms of the neighboring pixel rows, and when the frequency of the image data having the same luminance is equal to or greater than a preset threshold value, the neighboring pixel rows are the same. The method may include determining that the pixel rows are included in an area, and determining that the neighboring pixel rows are included in different areas when the frequency of the image data having the same luminance is less than the threshold value.

According to an exemplary embodiment, the detecting of the region maximum luminance and the region minimum luminance may include initializing the region maximum luminance and the region minimum luminance, and the row maximum luminance and row minimum luminance of the image data in units of pixel rows. Detecting , comparing the region maximum luminance with the row maximum luminance in each region, and comparing the region minimum luminance with the row minimum luminance in each region.

An image processing device according to embodiments of the present invention, a display device including the same, and an image processing method thereof convert image data in pixel row units to generate converted data, and based on the converted data, convert the image data into a plurality of areas. , and the contrast is improved for each region based on the region maximum luminance and region minimum luminance of each region, thereby improving the display quality of the display device. Also, an image processing device, a display device including the same, and an image processing method thereof may reduce memory capacity by converting image data in pixel row units using a line memory.

However, the effects of the present invention are not limited to the above-described effects, and may be variously extended within a range that does not deviate from the spirit and scope of the present invention.

1 is a block diagram illustrating an image processing device according to example embodiments.
FIG. 2 is a diagram for explaining an operation of a region divider included in the image processing device of FIG. 1 .
FIG. 3 is a block diagram for explaining the operation of the image processing device of FIG. 1 .
FIG. 4 is a diagram for explaining an example of a region divider included in the image processing device of FIG. 1 .
FIG. 5 is a diagram for explaining another example of a region divider included in the image processing device of FIG. 1 .
6 and 7 are diagrams for explaining the operation of a correction unit included in the image processing device of FIG. 1 .
8 is a block diagram illustrating a display device according to example embodiments.
FIG. 9 is a block diagram illustrating an electronic device including the display device of FIG. 8 .
10 is a diagram illustrating an example in which the electronic device of FIG. 9 is implemented as a smart phone.
11 is a flowchart illustrating an image processing method of a display device according to example embodiments.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. The same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

1 is a block diagram illustrating an image processing device according to embodiments of the present invention, FIG. 2 is a diagram for explaining an operation of a region divider included in the image processing device of FIG. 1, and FIG. It is a block diagram for explaining the operation of the image processing device.

Referring to FIG. 1 , the image processing device 100 may include a region divider 120 , a luminance detector 140 and a corrector 160 .

The region dividing unit 120 receives the image data ID[N], converts the image data ID[N] in units of pixel rows to generate converted data, and generates converted data based on the converted data (ID[N]). N]) into a plurality of regions, region division information RI[N] may be generated.

Referring to FIG. 2 , an image may be displayed on a display panel of a display device. The display device may display artificial images including characters or figures generated by software or the like and natural images including captured images or images transmitted from broadcasting stations. In particular, in the case of an artificial image, as shown in FIG. 2, the first to fourth regions (1ST REGION, 2ND REGION, 3RD REGION, 4TH REGION) including different information in a first direction (1ST DIRECTION) are included. can do. In this case, since each of the first to fourth regions 1ST REGION, 2ND REGION, 3RD REGION, and 4TH REGION includes images having different luminance, an optimal contrast ratio may be different for each region. The image processing device 100 according to embodiments of the present invention converts image data ID[N] for each pixel row (that is, along a first direction (1ST DIRECTION)) and displays a display panel based on the converted data. The display quality of the display device may be improved by dividing an image displayed in the second direction (2ND DIRECTION) into a plurality of regions and improving contrast for each region. Hereinafter, it will be described in detail with reference to FIG. 1 .

The region divider 120 may receive image data ID[N]. The region divider 120 reads the image data ID[N] for each pixel row, and divides the region of the image based on the image data ID[N] for each pixel row. RI[N]) can be generated. In an embodiment, the region divider 120 may filter the image data ID[N] in pixel row units using a linear filter to generate transform data, and determine boundaries of the regions based on the transform data. . The region divider 120 may output the boundaries of the regions as region division information RI[N]. The linear filter may detect a contour portion of an image based on image data ID[N]. For example, the linear filter may be selected from a group including any one of a high pass filter and a band pass filter. In this case, the region divider 120 may include a line memory that stores conversion data in units of pixel rows. The number of line memories may be determined according to the number of filter coefficients. For example, if you use a linear filter with 5 filter coefficients, you can include 5 rows of line memory, if you use a linear filter with 3 filter coefficients, you can include 3 rows of line memory. can do. In another embodiment, the region divider 120 outputs a histogram representing the luminance distribution corresponding to the image data ID[N] in units of pixel rows as conversion data, compares the histograms of neighboring pixel rows, and boundaries can be determined. The region division unit 120 compares the histograms of neighboring pixel rows and determines that the neighboring pixel rows are included in the same region when the frequency of the image data ID[N] having the same luminance is equal to or greater than a preset threshold. and if the frequency of the image data (ID[N]) having the same luminance is less than the threshold value, it may be determined that the neighboring pixel rows are included in different regions. The area divider 120 may include a line memory that stores conversion data in units of pixel rows. At this time, the capacity of the line memory may be reduced by dividing the luminance included in the histogram by region or by storing only image data (ID[N]) of a predetermined frequency or higher.

The luminance detection unit 140 reads the image data ID[N] for each pixel row, and the region of each region based on the image data ID[N] for each pixel row and the region division information RI[N]. A maximum luminance (L_MAX) and a region minimum luminance (L_MIN) may be detected. The luminance detector 140 may read the image data ID[N] for each pixel row, and detect a row maximum luminance and row minimum luminance of each row. The luminance detector 140 initializes the region maximum luminance L_MAX and region minimum luminance L_MIN in the first row of the corresponding region based on the region division information RI[N] supplied from the region divider 120. can For example, the luminance detector 140 may initialize the region maximum luminance L_MAX and region minimum luminance L_MIN of the first row of the region as shown in Equation 1.

<Equation 1>

L_MAX = 1.0

L_MIN = 0.0

At this time, L_MAX is the region maximum luminance, and L_MIN is the region minimum luminance. The luminance detector 140 compares the row maximum luminance in the same region with the region maximum luminance (L_MAX) as shown in Equation 2, resets the higher value to the region maximum luminance (L_MAX), and sets the row minimum luminance to the region minimum luminance (L_MIN). ), a lower value may be reset as the region minimum luminance (L_MIN).

<Equation 2>

L_MAX = max(L_MAX, LL_MAX)

L_MIN = min(L_MIN, LL_MIN)

At this time, L_MAX is the region maximum luminance, L_MIN is the region minimum luminance, LL_MAX is the row maximum luminance, and LL_MIN is the row minimum luminance.

Specifically, the luminance detector 140 calculates the maximum luminance of the row as the maximum luminance of the region (L_MAX) when the maximum luminance of the row of the m-th row (where m is a natural number equal to or greater than 2) has a value higher than the maximum luminance of the region (L_MAX). ), and when the row maximum luminance has a value lower than the region maximum luminance L_MAX, the region maximum luminance L_MAX may be maintained. In addition, when the row minimum luminance of the m-th row has a value lower than the region minimum luminance (L_MIN), the luminance detector 140 sets the row minimum luminance to the region minimum luminance (L_MIN), and the row minimum luminance is the region minimum luminance (L_MIN). When it has a value higher than the minimum luminance L_MIN, the value of the region minimum luminance L_MIN may be maintained. In this way, the luminance detector 140 can detect the region maximum luminance L_MAX and region minimum luminance L_MIN of each region. Although the region divider 120 and the luminance detector 140 are shown in FIG. 1 , the configuration of the image processing device 100 is not limited thereto. For example, the area divider 120 and the luminance detector 140 may be integrated so that conversion data generation and row maximum luminance and row minimum luminance detection may be simultaneously performed.

The correction unit 160 may generate corrected image data CD[N+1] for correcting the contrast of each region based on the region maximum luminance L_MAX and region minimum luminance L_MIN. The correction unit 160 corrects the current frame based on the region division information (RI[N]) of the image data (ID[N]) supplied from the previous frame, the region maximum luminance (L_MAX), and the region minimum luminance (L_MIN). Image data (CD[N+1]) may be generated. The correction unit 160 may extend the region maximum luminance L_MAX and region minimum luminance L_MIN for each region. Specifically, the display device displays an image having 0 to 225 gradations (ie, 8-bit driving), and the gradation value corresponding to the region minimum luminance (L_MIN) is a, and the gradation value corresponding to the region maximum luminance (L_MAX) is b, there is a margin of a for the grayscale value corresponding to the minimum luminance (L_MIN) of the region, and a margin of (225-b) for the grayscale value corresponding to the maximum luminance (L_MAX) of the region. can exist The correction unit 160 changes the grayscale value corresponding to the region minimum luminance (L_MIN) to correspond to a value between 0 and less than a, and changes the grayscale value corresponding to the region maximum luminance (L_MAX) to correspond to a value between b and 255 or less. And, by changing the gradation value corresponding to the image data (ID[N]) supplied to the region, the contrast of the image data (ID[N]) can be expanded. For example, the correction unit 160 may convert the image data ID[N] by using a linear function for each region. The correction unit 160 generates corrected image data (CD[N+1]) in which the contrast of each region is changed based on the region maximum luminance (L_MAX) and region minimum luminance (L_MIN) of each region, Correction image data (CD[N+1]) having an optimal contrast ratio can be generated for each.

As described above, the image processing device 100 of FIG. 1 converts the image data ID[N] in units of pixel rows to generate converted data, and generates the image data ID[N] based on the converted data. The display quality of the display device may be improved by dividing the display into a plurality of regions and improving the contrast for each region based on the region maximum luminance L_MAX and region minimum luminance L_MIN of each region. Also, the image processing device 100 may reduce the memory capacity by converting the image data ID[N] in units of pixel rows using a line memory.

FIG. 3 is a block diagram for explaining the operation of the image processing device of FIG. 1 .

Referring to FIG. 3 , the image processing device may generate region division information for dividing image data based on image data of a previous frame, and generate correction data of a current frame based on the region division information. Since the interval between frames is short enough to be imperceptible to the human eye (for example, 1/60 sec), and the artificial image includes a still image, there is little change in image data between frames. Region division information of the current frame may be substantially the same or similar. Accordingly, the image processing apparatus may analyze image data of a previous frame to generate region segmentation information for dividing a region, and improve contrast for each region based on the region division information in the current frame.

Specifically, the image processing device receives image data (ID[N-1]) of the (N-1)th frame, converts the image data of the (N-1)th frame in units of pixel rows, and generates converted data. and may generate region division information (RI[N-1]) for dividing the image data into a plurality of regions based on the converted data (where N is a natural number greater than or equal to 2). The image processing device may transfer region division information (RI[N-1]) generated in the (N−1) th frame to the N th frame. At this time, the region maximum luminance and region minimum luminance for each region detected based on the image data (ID[N-1]) of the (N-1)th frame together with the region division information (RI[N-1]) can be provided. Correction data for improving the contrast for each region of the image data (ID[N]) of the Nth frame based on the region segmentation information (RI[N-1]) provided in the (N-1)th frame in the Nth frame ( CD[N]).

FIG. 4 is a diagram for explaining an example of a region divider included in the image processing device of FIG. 1 .

Referring to FIG. 4 , a region divider of the image processing device may filter image data in pixel row units using a linear filter to generate transform data, and determine a boundary of a region based on the transform data. The linear filter may detect a contour portion of an image based on image data. In this case, the number of rows of the line memory may be determined according to filter coefficients of the linear filter. In case of 5 filter coefficients, 5 rows of line memory can be used, and in case of 7 filter coefficients, 7 rows of line memory can be used. The region divider reads image data as many rows as the number of rows of the line memory from the uppermost pixel row, and whenever processing of one row ends, image data of the next row may be input to the last row of the line memory. For example, when the linear filter is a Laplacian filter, the region may be divided based on an absolute value (hereinafter referred to as Laplacian absolute value) of a value of image data passing through the Laplacian filter. The region divider may determine the pixel row as a boundary between regions when image data supplied to the entire pixel row has the same value or has a preset value.

FIG. 5 is a diagram for explaining another example of a region dividing unit included in the image processing device of FIG. 1 .

Referring to FIG. 5 , the region dividing unit outputs a histogram representing a luminance distribution corresponding to image data in units of pixel rows as conversion data, and compares histograms of neighboring pixel rows to determine the boundary of the region. The region dividing unit may represent a distribution state of image data (eg, grayscale values) of each pixel row as a histogram. The region division unit compares the histograms of neighboring pixel rows, determines that the neighboring pixel rows are included in the same region when the number of image data having the same grayscale value is equal to or greater than a preset frequency, and determines the number of image data having the same grayscale value. When is less than the frequency, it may be determined that the neighboring pixel rows are included in different regions. Referring to FIG. 5, the region segmentation unit compares the histogram of the k-th row with the histogram of the (k+1)-th row, and since the frequency of image data having the same grayscale value G1 is greater than or equal to a preset threshold, the k-th histogram It may be determined that a row (k is a natural number of 1 or greater) and a (k+1)th row are included in the same area. In addition, the region segmentation unit compares the histogram of the (k+1)th row and the (k+2)th row, and since there is no image data having the same grayscale value (ie, the frequency of the image data is less than the threshold value), It may be determined that the (k+1)th row and the (k+2)th row are included in different regions. In addition, the region dividing unit compares the histogram of the (k+2)th row with the histogram of the (k+3)th row, and since the frequency of image data having the same grayscale value (G2) is greater than or equal to a preset threshold value, (k+3) It may be determined that the 2)th row and the (k+3)th row are included in the same area. The region divider may store image data in a line memory in units of pixel rows. At this time, the capacity of the line memory may be reduced by dividing the grayscale values included in the histogram by region or by storing only image data occupying a predetermined frequency or more among image data provided to each row. For example, the line memory required to process 1440x2560 image data is 1,440 (width) x 3 (RGB) x 8 (depth) = 34,650 bits per row, but the grayscale value area is divided by 10, and the When the histogram is stored using only image data occupying 2% or more of the image data, a memory capacity of 4,588 bits per row is required and may be less than 0.2 rows of line memory.

6 and 7 are diagrams for explaining the operation of a correction unit included in the image processing device of FIG. 1 .

Referring to FIG. 6 , the correction unit may extend the region maximum luminance and the region maximum luminance. Referring to FIG. 6 , when the display device displays an image having 0 to 225 gradations (ie, 8-bit driving), the gradation value corresponding to the minimum luminance of the region is a, and the gradation value corresponding to the maximum luminance of the region is b. , there may be a margin of a for the grayscale value corresponding to the minimum luminance, and a margin of (255-b) for the grayscale value corresponding to the maximum luminance. The correction unit changes the gradation value corresponding to the minimum luminance of the region to correspond to a value (a') of 0 or more and less than a, and changes the gradation value corresponding to the maximum luminance to correspond to a value (b') greater than b and less than 1, and Contrast can be extended by changing the gradation value corresponding to the supplied image data. For example, the correction unit may convert image data using a linear function such as Equation 3.

<Equation 3>

At this time, CD is the correction data, ID is the image data, a is the grayscale value corresponding to the minimum luminance of the region, b is the grayscale value corresponding to the maximum luminance of the region, a' is the grayscale value corresponding to the minimum luminance of the conversion, and b' is the grayscale value corresponding to the minimum luminance of the region. It may be a grayscale value corresponding to the changeable maximum luminance. Accordingly, as shown in FIG. 7 , corrected image data having an optimal contrast ratio for each region may be generated.

8 is a block diagram illustrating a display device according to example embodiments.

Referring to FIG. 8 , the display device 200 may include a display panel 210 , an image processor 220 , a data driver 230 , a scan driver 240 and a timing controller 250 .

The display panel 210 may include a plurality of pixels. A plurality of data wires and a plurality of scan wires may be formed in the display panel 210 . A plurality of pixels may be formed in an area where data lines and scan lines intersect. In one embodiment, each of the pixels may include a pixel circuit, a driving transistor, and an organic light emitting diode. In this case, when the pixel circuit transmits the data signal DATA supplied from the data line to the driving transistor in response to the scan signal SCAN supplied from the scan line, the driving transistor operates the organic light emitting diode based on the data signal DATA. A driving current flowing through may be adjusted, and the organic light emitting diode may emit light based on the driving current.

The image processor 220 converts the image data ID corresponding to the image displayed on the display panel 210 for each pixel row, divides the image data ID into a plurality of regions based on the converted data, and divides the image data ID into a plurality of regions, respectively. Compensation image data (CD) for correcting the contrast of each region may be generated based on the maximum luminance of the region and the minimum luminance of the region. The image processor 220 receives the image data (ID) of the previous frame, generates region division information for dividing a region of the image data (ID), and applies the region division information to the image data (ID) of the current frame. Compensation image data (CD) for correcting contrast for each region may be generated. Specifically, the image processing unit 220 may include a region segmentation unit, a luminance detection unit, and a correction unit. The region divider receives the image data ID, converts the image data ID in pixel row units to generate converted data, and divides the image data ID into a plurality of regions based on the converted data. information can be generated. In an embodiment, the region dividing unit may filter the image data ID in pixel row units using a linear filter to generate transformed data, and determine a boundary of the region based on the transformed data. The linear filter may detect a contour portion of an image based on the image data ID. In this case, the region divider may include a line memory for storing conversion data in units of pixel rows. In another embodiment, the region divider may output a histogram representing a distribution of luminance corresponding to image data in units of pixel rows as conversion data, and compare histograms of neighboring pixel rows to determine the boundary of the region. The region division unit compares the histograms of neighboring pixel rows, determines that the neighboring pixel rows are included in the same region when the number of image data having the same luminance is equal to or greater than a predetermined threshold, and determines the number of image data having the same luminance. When is less than the threshold value, it may be determined that the neighboring pixel rows are included in different regions. The area divider may include a line memory that stores conversion data in units of pixel rows. The luminance detector may read the image data ID for each pixel row and detect a region maximum luminance and region minimum luminance of each region based on the image data ID for each pixel row. The luminance detector initializes the region maximum luminance and region minimum luminance in the first row of the corresponding region based on the region division information supplied from the region divider, and the row maximum luminance, region maximum luminance, row minimum luminance, and region minimum luminance within the same region. A region maximum luminance and region minimum luminance may be detected by comparing the luminance. The correction unit may generate corrected image data (CD) for correcting the contrast of each region based on the maximum luminance of the region and the minimum luminance of the region. The correction unit may expand the region maximum luminance and region minimum luminance for each region.

The data driver 230 may generate a data signal DATA based on correction data supplied from the image processor 220 and supply the data signal DATA to pixels. The data driver 230 generates a data signal DATA corresponding to the correction data CD in response to the first control signal CTL1 supplied from the timing controller 250, and transmits the data signal DATA to the display panel ( 210) can be output to the data line.

The scan driver 240 may supply scan signals SCAN to the pixels. The scan driver 240 generates a scan signal SCAN in response to the second control signal CTL2 supplied from the timing controller 250 and outputs the scan signal SCAN to a scan line of the display panel 210. can

The timing controller 250 may receive image data ID from the outside. The timing controller 250 may supply the image data ID to the image processor 220 . Also, the timing controller 250 may generate a first control signal CTL1 for controlling the data driver 230 and a second control signal CTL2 for controlling the scan driver 240 . The timing controller 250 may output the first control signal CTL1 to the data driver 230 and output the second control signal CTL2 to the scan driver 240 . 8 shows that the image processor 220 and the timing controller 250 are connected, the image processor 220 may be included in the timing controller 250 .

As described above, the display device 200 of FIG. 8 divides the image data ID into a plurality of regions, and detects the region maximum luminance and region minimum luminance of each region to improve contrast for each region. By including 220, display quality can be improved. In addition, the image processing unit 220 may reduce the memory capacity by converting the image data ID in pixel row units using the line memory and dividing the regions into regions.

9 is a block diagram illustrating an electronic device including the display device of FIG. 8 , and FIG. 10 is a diagram illustrating an example in which the electronic device of FIG. 9 is implemented as a smart phone.

9 and 10, the electronic device 300 includes a processor 310, a memory device 320, a storage device 330, an input/output device 340, a power supply 350, and a display device 360. can include In this case, the display device 360 may correspond to the display device 200 of FIG. 1 . Furthermore, the electronic device 300 may further include several ports capable of communicating with video cards, sound cards, memory cards, USB devices, etc., or with other systems. Meanwhile, as shown in FIG. 10 , the electronic device 300 may be implemented as a smart phone 400, but the electronic device 300 is not limited thereto.

Processor 310 may perform certain calculations or tasks. In one embodiment, the processor 310 may be a microprocessor, central processing unit (CPU), or the like. The processor 310 may be connected to other components through an address bus, a control bus, and a data bus. In addition, the processor 310 may be coupled to an expansion bus such as a Peripheral Component Interconnect (PCI) bus. The memory device 320 may store data necessary for the operation of the electronic device 300 . For example, the memory device 320 may include EPROM, EEPROM, flash memory, phase change random access memory (PRAM), resistance random access memory (RRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), and the like. and/or volatile memory devices such as dynamic random access memory (DRAM), static random access memory (SRAM), and mobile DRAM. The storage device 330 may include a solid state drive (SSD), a hard disk drive (HDD), a CD-ROM, and the like.

The input/output device 340 may include an input means such as a keyboard, a keypad, a touch pad, a touch screen, and a mouse, and an output means such as a speaker and a printer. The display device 360 may be included in the input/output device 340 . The power supply 350 may supply power necessary for the operation of the electronic device 300 . The display device 360 may be connected to other components through the buses or other communication links.

As described above, the display device 360 may include a display panel, an image processor, a data driver, a scan driver, and a timing controller. The display panel may include a plurality of pixels, data lines, and scan lines. A plurality of pixels may be formed in an area where data lines and scan lines intersect. The image processing unit converts image data corresponding to the image displayed on the display panel for each pixel row, divides the image data into a plurality of regions based on the converted data, and based on the region maximum luminance and region minimum luminance of each region. Thus, correction image data for correcting the contrast of each region may be generated. The image processing unit receives the image data of the previous frame, generates region segmentation information for dividing regions of the image data, and applies the region division information to image data of the current frame to generate correction image data for correcting contrast for each region. can In an embodiment, the image processor may generate transformed data by filtering image data in pixel row units using a linear filter, and determine a boundary of a region based on the transformed data. In another embodiment, the image processing unit may output a histogram representing a luminance distribution corresponding to image data in units of pixel rows as conversion data, and compare the histograms of neighboring pixel rows to determine the boundary of the region. The image processing unit may read image data for each pixel row and detect a region maximum luminance and region minimum luminance of each region based on the image data for each pixel row. The image processing unit may compare the maximum luminance of a row and the maximum luminance of a region in each region to detect the maximum luminance of the region, and may compare the minimum luminance of a row and the minimum luminance of the region to detect the minimum luminance of the region. The image processing unit may improve the contrast of each region of the image data by extending the region maximum luminance and region minimum luminance for each region. The data driver may generate a data signal based on correction data supplied from the image processor and supply the data signal to the pixels. The scan driver may supply scan signals to the pixels. The timing controller may receive image data from the outside. The timing controller may supply image data to the image processor. Also, the timing controller may supply the first control signal to the data driver and the second control signal to the scan driver.

As described above, the electronic device 300 of FIG. 9 includes a display device that divides image data into a plurality of regions, detects the region maximum luminance and region minimum luminance of each region, and improves the contrast for each region. , the display quality can be improved. In addition, the display device 360 converts image data in pixel row units using a line memory to divide regions, thereby reducing memory capacity.

11 is a block diagram illustrating an image processing method of a display device according to example embodiments.

Referring to FIG. 11 , an image processing method of a display device includes dividing image data into a plurality of regions (S100), detecting a region maximum luminance and a region minimum luminance of each region (S200), and contrast of each region. It may include a step of correcting (S300).

The image processing method of the display device may generate converted data by converting image data in units of pixel rows, and divide the image data into a plurality of regions based on the converted data ( S100 ). In an embodiment, the image processing method of the display device may generate converted data by filtering image data in pixel row units using a linear filter. Boundaries of the regions may be determined based on the conversion data. The linear filter may be selected from a group including any one of a high pass filter and a band pass filter. For example, when using a Laplacian filter, image data may be converted into absolute Laplacian values, and a pixel row including image data having the same absolute Laplacian value may be determined as a boundary of a region. In another embodiment, the image processing method of the display device may output a histogram representing a luminance distribution corresponding to image data in pixel row units as converted data. In this case, the boundaries of the regions may be determined by comparing histograms of neighboring pixel rows. The image processing method compares histograms of neighboring pixel rows, determines that the neighboring pixel rows are included in the same area when the frequency of the image data having the same luminance is equal to or greater than a preset threshold, and determines that the image data having the same luminance When the frequency of is less than or equal to a preset threshold, it may be determined that neighboring pixel rows are included in different regions.

The image processing method of the display device may detect a region maximum luminance and region minimum luminance of each region based on image data ( S200 ). The image processing method of the display device may minimize the region maximum luminance and region minimum luminance in a pixel row where the region starts, and detect the row maximum luminance and row minimum luminance of image data in units of pixel rows. In addition, the region maximum luminance may be detected by comparing the region maximum luminance with the row maximum luminance within each region, and the region minimum luminance may be detected by comparing the region minimum luminance with the row minimum luminance.

The image processing method of the display device may generate correction image data for correcting the contrast of each region based on the maximum luminance of the region and the minimum luminance of the region ( S300 ). The image processing method of the display device may improve the contrast of each region by extending a luminance range in which image data is output based on the region maximum luminance and region minimum luminance of each region.

As described above, the image processing method of the display device improves display quality by dividing image data into regions, detecting region maximum luminance and region minimum luminance for each region, and extending the range of maximum luminance and minimum luminance for each region. can make it

The present invention can be applied to all electronic devices equipped with a display device. For example, the present invention relates to televisions, computer monitors, notebooks, digital cameras, mobile phones, smart phones, smart pads, tablet PCs, PDAs, PMPs, MP3 players, navigation devices, video phones, head mounted displays ( It can be applied to Head Mount Display (HMD) devices and the like.

Although the above has been described with reference to exemplary embodiments of the present invention, those skilled in the art can make various modifications to the present invention within the scope not departing from the spirit and scope of the present invention described in the claims below. It will be understood that it can be modified and changed accordingly.

100: image processing device 120: region dividing unit
140: luminance detection unit 160: correction unit
200: display device 210: display panel
220: image processing unit 230: data driving unit
240: scan driver 250: timing controller

Claims (20)

Receiving image data corresponding to an image displayed on the display panel, converting the image data for each pixel row defined by all pixels constituting one row of the display panel to generate conversion data, a region divider configured to generate region division information for dividing the image data into a plurality of regions based on the above;
a luminance detector configured to detect a region maximum luminance and region minimum luminance of each region based on the image data and the region division information; and
and a correction unit configured to generate correction image data for correcting contrast of each region based on the region division information, the maximum luminance of the region, and the minimum luminance of the region. The image of claim 1 , wherein the correction unit generates the corrected image data of the current frame based on the region division information, the maximum luminance of the region, and the minimum luminance of the region of the image data supplied from a previous frame. processing unit. The method of claim 1 , wherein the region divider filters the image data in units of pixel rows using a linear filter to generate the converted data, and determines boundaries of the regions based on the converted data. image processing device. The image processing apparatus according to claim 3, wherein the linear filter is selected from a group including one of a high pass filter and a band pass filter. The method of claim 1 , wherein the region divider outputs a histogram representing a luminance distribution corresponding to the image data in units of pixel rows as the converted data, and compares the histograms of neighboring pixel rows to determine boundaries of the regions. An image processing device characterized in that for determining. The method of claim 5 , wherein the region divider compares the histograms of the neighboring pixel rows, and when the frequency of the image data having the same luminance is equal to or greater than a preset threshold, the neighboring pixel rows are included in the same region. and if the frequency of the image data having the same luminance is less than the threshold value, it is determined that the neighboring pixel rows are included in different regions. The image processing device of claim 1 , wherein the area divider comprises a line memory to store the converted data in units of pixel rows. The method of claim 1 , wherein the luminance detection unit detects a row maximum luminance and a row minimum luminance of the image data for each pixel row, and compares the maximum luminance and the minimum luminance of the pixel rows in each region to The image processing device characterized by detecting the region maximum luminance and the region minimum luminance of each region. The image processing apparatus according to claim 1 , wherein the correction unit expands the region maximum luminance and region minimum luminance for each region. a display panel including a plurality of pixels;
Image data corresponding to the image displayed on the display panel is converted for each pixel row defined by all pixels constituting one row of the display panel, and the image data is divided into a plurality of regions based on the converted data. an image processing unit configured to perform segmentation and to generate correction image data for correcting contrast of each region based on the region maximum luminance and region minimum luminance of each region;
a data driver generating a data signal based on the corrected image data and supplying the data signal to the pixels;
a scan driver supplying scan signals to the pixels; and
and a timing controller configured to generate a control signal for controlling the data driver and the scan driver. 11. The method of claim 10, wherein the image processing unit divides the regions based on the image data supplied from a previous frame and generates the corrected image data of the current frame based on region division information for dividing the regions. display device to be. 11. The method of claim 10 , wherein the image processing unit filters the image data in units of pixel rows using a linear filter to generate the converted data, and determines boundaries of the regions based on the converted data. display device. 11. The method of claim 10, wherein the image processing unit outputs a histogram representing a luminance distribution corresponding to the image data in units of pixel rows as the converted data, and compares the histograms of neighboring pixel rows to determine boundaries of the regions. A display device characterized in that for determining. 11 . The display device of claim 10 , wherein the image processing unit expands the region maximum luminance and region minimum luminance for each region. Converting image data corresponding to an image displayed on the display panel for each pixel row defined by all pixels constituting one row of the display panel to generate conversion data, and converting the image data into a plurality of pieces based on the conversion data. Dividing into regions of;
detecting a region maximum luminance and a region minimum luminance of each region based on the image data; and
and generating correction image data for compensating the contrast of each region based on the maximum luminance of the region and the minimum luminance of the region. The image of the display device of claim 15 , wherein the converted data is generated by filtering the image data in units of pixel rows using a linear filter, and boundaries of the regions are determined based on the converted data. processing method. 17. The method of claim 16, wherein the linear filter is selected from a group including one of a high pass filter and a band pass filter. 16. The method of claim 15 , wherein a histogram representing a luminance distribution corresponding to the image data in units of pixel rows is output as the converted data, and boundaries of the regions are determined by comparing the histograms of neighboring pixel rows. An image processing method of a display device comprising: 19. The method of claim 18, wherein dividing the region comprises
comparing the histograms of the neighboring pixel rows;
determining that the neighboring pixel rows are included in the same area when the frequency of the image data having the same luminance is equal to or greater than a preset threshold; and
and determining that the neighboring pixel rows are included in different regions when the frequency of the image data having the same luminance is less than the threshold value. 16. The method of claim 15, wherein detecting the region maximum luminance and the region minimum luminance
initializing the region maximum luminance and the region minimum luminance;
detecting row maximum luminance and row minimum luminance of the image data in units of pixel rows;
comparing the region maximum luminance and the row maximum luminance within each region; and
and comparing the minimum luminance of the region and the minimum luminance of the row in each of the regions.

Images